Sliding sleeve valves have been used in tubing string for oil and gas wells to control fluid flow between the tubing string and the well annulus during circulation or production. The valves contain an inner sliding sleeve having a port that can be shifted to an opened position in alignment with a port in the outer valve body to permit fluid to flow from the tubing string to the well annulus. Shifting the sliding sleeve to a closed position blocks the port in the valve body to prevent the fluid from flowing into the well annulus. Mechanical sliding sleeve valves are manipulated by shifting tools customarily deployed on wireline or slickline. Shifting tools move the sliding sleeve to either the fully shifted up or fully shifted down position. Accordingly, sliding sleeve valves customarily have only two positions opened or closed.
Sliding sleeve valves have been developed that have a third position known as the equalizing position. The equalizing position is located intermediate of the opened and closed positions. In these valves, a smaller diameter equalizing port is provided in the inner sliding sleeve. The equalizing port serves to balance the tubing pressure and the annulus pressure before fully opening the valve in order to reduce the likelihood of a pressure surge as the valve is fully opened. The process of equalizing the pressures is carried out by shifting the sliding sleeve to a position where the equalizing port in the sliding sleeve is in fluid communication with the port of the valve body. Shifting tools have been produced to manipulate such sliding sleeve valves. U.S. Pat. No. 5,305,833, which is incorporated herein by reference, describes a shifting tool capable of positioning a sliding sleeve valve in a fully closed position, equalizing position, and fully opened position.
Multi-positioned sliding sleeve valves have also been developed. U.S. Pat. No. 6,722,439, which is incorporated herein by reference, describes a downhole choke valve in the form of a hydraulically controlled sliding sleeve valve operable in a plurality of positions including fully opened, fully closed and intermediate positions.
Despite the development of shifting tools that can position a sliding sleeve valve in three distinct positions, fully closed, equalizing, and fully opened, the need still exists for a shifting tool that can position a mechanical sliding sleeve valve in multiple positions and which can be used in conjunction with a multiple position mechanical choke valve.